In recent years, the breakthrough of AI technology on both of software and hardware leads to a new and beneficial development of robotics. Bionic flexible robots that have developed rapidly, compared to conventional robots with rigid structures, have some obvious advantages in underwater exploration, fire rescue and military.
A dielectric elastomer is capable of more than 100% deformation when an appropriate electric field is applied, and due to its characteristics of light weight, low noise, high efficiency, high strain and high flexibility, it is often used as artificial muscles in the bionic flexible robots. In order to extend to different applications, the dielectric elastomer has derived more excellent materials, such as electroactive materials with a high frequency response range and without pre-stretching. Wings of small birds have a high vibration frequency, for example, hummingbird's wings can vibrate at a frequency up to 80 Hz. Therefore, the dielectric elastomer of fast response makes it possible to achieve a small bionic bird.
There still many problems exist in the applications of the dielectric elastomer despite of its excellent properties. First, only less than 10% of electric field energy applied to the dielectric elastomer is converted to a mechanical energy in each conversion, and the remaining energy needs to be fed back to a power supply by a circuit or be directly dissipated by a resistor. The dissipation through the resistor will greatly reduce the efficiency of the circuit, thereby reducing the overall system efficiency. Second, in applications of a fast-responding dielectric elastomer, the power supply circuit is required to reach a sufficient charging and discharging speed. In a discontinuous conduction mode (DCM), the charging and discharging time of a bidirectional flyback topology are inversely proportional to the supply voltage and the peak current of the primary transformer. However, in practical applications, a lithium battery or a button battery is commonly used as a power source, which is boosted to a high voltage through a DC-DC circuit. Since the supply voltage and the peak current available are limited, the charging speed may be limited by the lower voltage and the current of charging. The cycle time of charging and discharging can be reduced by increasing turns ratio of the transformer, but it will greatly increase the size and design difficulty of the converter and increase voltage stress of the secondary MOSFET.
Therefore, in order to achieve the fast charging and discharging of dielectric elastomers, it is urgent to propose an improved bidirectional flyback circuit to increase the charging and discharging speed.